Transistor cap remover



July 14, 1970 FIG.

R. A. TOLKMITT TRANSISTOR CAP REMOVER Filed April 10, 1968 I 1\-' VENTOR. RICHARD A. TOLKMITT V. C. MULLER ROY MILLER ATTORNEYS,

United States Patent O 3,520,218 TRANSISTOR CAP REMOVER Richard A.Tolkmitt, China Lake, Califi, assignor to the United States of Americaas represented by the Secretary of the Navy Filed Apr. 10, 1968, Ser.No. 720,135 Int. Cl. B23]: 3/04, 5/14 U.S. C]. 82-92 1 Claim ABSTRACT OFTHE DISCLOSURE Method and apparatus for severing the side wall of atransistor can to expose its contained electronic com ponent, such as ase-miconductor chip, without producing cuttings from the can wall whichcould contaminate or otherwise injure the component.

BACKGROUND OF THE INVENTION In the repair of malfunctioning circuits,employing semiconductor chips which are enclosed in cans, it has beenthe practice to cut the can sidewall to expose the chip for inspection.If the chip is reuseable it has been found economical to remove it andrepackage it for use in a circuit. In one method of cutting the can wallthe can was rotated in a lathe and the wall severed with a parting tool.This, however, produced metal cuttings which could injure the chip orthe chip could otherwise be injured when the severed part, to which thechip is aflixed, dropped from the lathe chuck.

Another method of opening the can was to sever it with a chisel or liketool which could also injure the chip if impacted by the tool.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an isometric view of theinvention, and FIG. 2 is an enlarged longitudinal cross section of aworkpiece.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 2,transistor can is formed with a cylindrical metallic wall 12 and anintegral end wall 14, the opposite end being closed by a cup shapedclosure 16, having a flange 18, and an end wall 20 to which is affixedchip 22. The purpose of the invention is to sever wall 12 at a desiredplane P without producing chips from wall 12.

Referring to FIG. 1, the apparatus for performing the method aforesaidcomprises a C shaped frame 24 to which is journaled a knurled driveroller 26 and a plain roller 28, the knurled roller being afiixed to ashaft 30 having a hand crank 32 on the end of same. Each roller isprovided with a groove 34, into which flange 18 of cup shaped closure 16may project when wall 12 is lying on the rollers.

A cutter wheel head 36 is supported by the frame for rectilinearmovement, and is fed toward the rollers by a conventional screw (notshown) contained within rotatable feed knob 38, the cutter head having acircular knife shaped cutter 39 journaled to same. Frame 24 ispreferably aflixed to a rigid support 40 which may be affixed to a benchor the like.

In the operation of the apparatus can 10 is placed on the rollers withflange 18 disposed in grooves 34 and the cutter wheel moved into contactwith the can with sufficient pressure to cause the teeth on the knurledroller to slightly indent the can wall and provide a positive drive tothe can wall as it is rotated by the crank. A slight increase in thefeed of the cutting wheel, as the crank is rotated severs the can wallwithout the production of chips.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is therefore to beunderstood that within the sco of the appended claims the invention maybe practiced otherwise than as specifically described.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

What is claimed is:

.1. Apparatus for severing the side wall of a cylindrical transistorcontainer comprising:

(a) an easily portable base member having an upstanding support memberthereon,

(b) an open C-shaped frame member aflixed to said support member,

(c) first and second rotative work support rolls parallelly mounted atone extremity of said C-shaped frame,

(d) an infinitely manually adjustable feed circular knife cutter beingfreely rotatably mounted at another extremity of said C-shaped memberwith the axis of the said knife being aligned and parallel to the axesof the said rolls,

(e) each of said rolls having transversely aligned grooves that areoffset from the plane of cut of the said circular knife cutter in orderto receive any appendicies of a transistor container, and

(f) one of said rolls being knurled and utilizing as its rotativesupport shaft one arm of a hand crank directly attached thereto,

(g) the construction and arrangement being such that the one of saidrolls along with the said hand crank thereon provides rotative impetusto the apparatus as well as support for a transistor container inassociation with the other of said rolls and wherein the open C-shapedframe provides a clear field of vision during operation of the saidapparatus.

References Cited UNITED STATES PATENTS 1,042,998 10/1912 Blackmore 82-91X 1,256,556 2/1918 Hedges 82-4 X 1,304,770 5/1919 Hestand 30-1021,468,935 9/1923 Vosper 82-101 X 2,065,138 12/1936 Lang 30-102 2,582,078l/ 1952 Solum et al. 82-92 2,753,739 7/1956 Dreier 77-73 X 2,753,7447/1956 Therien 30-97 X 3,125,915 3/1964 Ahearn 82-101 X HARRISON L.HINSON, Primary Examiner U.S. Cl. X.R. 30-102

